Sanitary napkin or an incontinence guard having flexible side-flaps

ABSTRACT

The invention relates to an absorbent article, such as a sanitary napkin or an incontinence guard intended to be worn in the crotch part of a pair of underpants (9), and comprising an elongated absorbent pad (3) which is enclosed in a casing (1, 2) and which has attached to both long side edges (6, 7) flexible flaps (4, 5) which are intended to be folded around the leg edges (10, 11) of the underpants (9) in use, so as to prevent soiling of the underpants. An inventive article is mainly characterized in that each flap (4, 5) has an edge part which coincides generally with a corresponding edge part on the article casing (1, 2), and in that the flaps (4, 5) and the casing (1, 2) are mutually joined within the mutually coincidental edge parts (12, 13), with the flaps (4, 5) extending inwardly over the absorbent pad (3).

FIELD OF THE INVENTION

The present invention relates to an absorbent article, such as asanitary napkin or an incontinence guard, intended to be worn in thecrotch part of a pair of underpants and including an elongated absorbentpad enclosed in a casing, and flexible flaps which are attached torespective long edges of said pad, said flaps being formed of separatematerial pieces and intended to be folded around the leg edges of theunderpants in use, so as to protect the underpants against soiling.

BACKGROUND OF THE INVENTION

Articles of this kind are intended to be worn by menstruating women orby persons who suffer from relatively light incontinence, and whorequire the articles to afford protection against leakage but still beunnoticeable when worn beneath conventional clothing. Since the amountof fluid discharged with menstruation and with light incontinence isrelatively small, the articles can be designed in a manner which enablesthem to be accommodated essentially fully in the crotch region, betweenthe wearer's thighs. The requirement that such articles shall bediscrete when worn is satisfied almost to the full by said articles.

However, it has been found difficult to produce articles of this kindwhich are sufficiently proof against leakage. The main reason for thisis that, when worn, the articles are highly deformed by the forces thatare generated as the wearer moves. The greatest deformation normallyoccurs within that part of the article which, in use, is located in thenarrowest space between the wearer's thighs. Unfortunately, this part ofthe article is also the part which is intended to receive the dischargedbody fluid first and to absorb said fluid. As a result of thispronounced deformation of the article, the surface area of the articleavailable for direct absorption is, of course, greatly reduced. Thisincreases the risk of body fluid leaking past the side edges of thearticle and soiling the user's underpants.

A number of different methods of reducing the risk of lateral leakagehave been proposed. For example, SE 455 668, U.S. Pat. No. 4,285,343, EP130 848, EP 134 086 and U.S. Pat. No. 4,608,047 teach sanitary napkinswhich are provided with flexible flaps, or wings, that protrudeoutwardly from the absorbent pad. These flaps are intended to be foldedaround the edges of the leg openings of the wearer's underpants or likegarment and fastened to the outside of said underpants when fitting thenapkin for use. The flaps thereby form a protective guard against thelateral leakage of body fluids and soiling of the underpants.

These earlier known, so-called winged sanitary napkins are encumberedwith several drawbacks, however. For example, sanitary napkins of thiskind are found difficult to manipulate by many users, mainly because ofthe difficulty found in folding and shaping the wings around the curvededges of the leg openings of a pair of underpants or like garment. Thisproblem is particularly manifest in the case of sanitary napkins whosewings or side-flaps have large extensions in the longitudinal directionof the article, since it is necessary to fold the wings around arelatively large part of the leg edges of the underpants. Wings whichextend along only a small part of respective side edges of the napkincan be folded around the edges of the leg openings more easily, butthese flaps, naturally, provide much poorer protection against leakagethan the large flaps.

The known winged sanitary napkins are normally secured to the underpantsof the wearer by means of pressure-sensitive adhesive provided on thewings, in the form of adhesive beads, strings or the like along thelongitudinal center line of the napkin, on that side of the napkin whichis distal from the wearer in use. Prior to use, the pressure-sensitiveadhesive is covered with a protective release strip, which is removedwhen the binder is to be secured to the wearer's underpants.

When securing winged sanitary napkins of this kind to the wearer'sunderpants, the work involved in removing the various protective layersand in folding and securing the wings is quite comprehensive.Furthermore, the work involved must be carried out in the correctsequence in order to avoid prematurely exposed adhesive surfaces fromfastening to the underpants in the wrong places and therewith making itdifficult to position the napkin correctly.

The known winged sanitary napkins normally comprise an absorbent padwhich is enclosed by two casing sheets. These sheets extend beyond theside edges of the absorbent pad, to form the wings of the napkin. This,of course, is a simple construction which affords certain manufacturingadvantages. However, a great deal of material is wasted when cuttingsuch napkins to shape, which is obviously a disadvantage. Furthermore,it is necessary to fold the wings together so that the napkins can bepackaged, which complicates the manufacturing process.

Furthermore, the fact that the napkin casing material merges directlywith the wings is disadvantageous from a purely functional aspect, sincebody fluid can then be transported from the absorbent pad to the wings,causing leakage.

The present invention provides an article of the aforedescribed kindwhich avoids the drawbacks associated with known articles of this kind.

SUMMARY OF THE INVENTION

An article constructed in accordance with the invention is mainlycharacterized in that each flap has an edge part which coincidesgenerally with a corresponding edge part on the article casing; and inthat the flaps and the casing are mutually Joined within the mutuallycoincident edge parts, with the flaps facing each other with their freeedge parts extending inwardly over the absorbent pad on the side of thecasing remote from the wearer when the article is in use.

According to one embodiment of the invention, the longitudinallyextending side edges have a concave curvature, thereby imparting to thearticle a shape which conforms generally with the shape of the crotch ofa pair of underpants or like garment.

According to another embodiment, the flaps extend along the whole lengthof the side edges of the article.

According to another embodiment, the casing includes a liquid-permeablesheet on that side of the object which faces the user in use, and aliquid-impermeable sheet on that side of the article which is distalfrom the wearer in use, said two sheets projecting out beyond the edgesof the absorbent pad and being mutually joined around the full peripheryof the absorbent pad, wherein the flexible flaps are secured in thecasing edge of the liquid-impermeable sheet that projects out from theabsorbent pad.

According to a further embodiment, the regions of pressure-sensitiveadhesive are provided on the liquid-impermable sheet.

According to a further embodiment, the regions of pressure-sensitiveadhesive are provided on the flexible flaps.

A number of advantages are gained when flaps are arranged on anabsorbent article in accordance with the present invention, such thatthe flaps are directed in over the article instead of extending straightout from the side edges of said article, as with the case of the earlierknown sanitary napkins.

For example, it enables the articles to be manufactured with negligiblewastage of material when cutting-out the articles. Furthermore, thearticles can be packaged more readily, since it is not necessary to foldthe flaps together.

Furthermore, the flaps are made from separate pieces of material, whosecomposition and other properties can be freely selected, independentlyof the material from which the article casing is made. In addition,there is no direct connection between the casing or the absorbent pad ofthe article and the flaps, thereby interrupting all liquid transportpaths therebetween. The joins between the flaps and the remainder of thearticle thus form a type of leakage barrier.

Further advantages are gained when the flaps are attached on that sideof the article which is distal from the wearer in use. For instance,this enables an article to be produced which is shaped according to thecurved leg edges of a pair of underpants or like garment. When anarticle of this kind is placed in a pair of underpants, the leg edges ofthe underpants are inserted between the flaps and the casing material onthe underside of the article, i.e. on that side of the article which isworn distal from the wearer. In use, the article becomes curved in itslongitudinal direction, so as to conform to the shape of that part ofthe wearer's body. This results in tension forces in the flaps, whichpress the flaps against the casing material on the underside of thearticle and firmly clamp the leg edges of the underpants between theflaps and the remainder of the article. This "self-locking" of thearticle to the underpants can obviate the use of separate fastenermeans, such as adhesive beads or the like. This naturally affords animportant advantage, since it enables the article to be handled muchmore easily, both when positioning the article in a pair of underpantsand when removing the used article therefrom. Furthermore, the articlescan be manufactured much more simply and more cheaply when it is nolonger necessary to provide the articles with attachment adhesive andassociated protective tapes.

BRIEF DESCRIPTION OF THE DRAWINGS

An inventive absorbent article will now be described in more detail withreference to exemplifying embodiments thereof and also with reference tothe accompanying drawings.

FIG. 1 shows an inventive sanitary napkin from above, as seen from thatside of the napkin which faces the wearer in use, with the napkin shownfitted inside a pair of underpants.

FIG. 2 illustrates the napkin of FIG. 1 as seen from that side of thenapkin which is distal from the wearer in use.

FIG. 3 is a sectional view of the napkin shown in FIG. 1, taken on theline III--III in said Figure.

FIG. 4 illustrates a second embodiment of an inventive sanitary napkin,seen from the side of the napkin which is distal from the wearer in use.

FIG. 5 illustrates a sanitary napkin according to a third embodiment ofthe invention, seen from the side of the napkin which is distal from thewearer in use, and

FIG. 6, finally, is a sectional view of the napkin of FIG. 5 placedwithin a pair of underpants, in the region of the wearer's crotch.

DETAILED DESCRIPTION OF THE INVENTION

The sanitary napkin illustrated in FIGS. 1-3 includes a liquid-permeablecasing sheet 1, which is placed on that side of the napkin which facesthe wearer in use. The liquid-permeable sheet 1 is suitably made from anonabsorbent fabric, or from a perforated plastic fill. The sanitarynapkin further includes a liquid-impermeable casing sheet 2, for examplea plastic fill or a fabric, which has been made hydrophobic on that sideof the napkin which is distal from the wearer in use. An absorbent pad 3is enclosed between the two casing sheets 1, 2. The absorbent pad 3 maycomprise one or more layers of absorbent material, such as cellulosefluff, with or without being admixed with so-called superabsorbents. Bysuperabsorbents is meant polymeric materials which are capable ofabsorbing liquid in amounts corresponding to many times their ownweight. Superabsorbents normally have the form of particles, which areadmixed with the cellulose fluff, or are applied in separate layersbetween mutually adjacent fluff layers. Superabsorbents may also be inthe form of flakes, granules, films and fibers, as an alternative to aparticle form.

Although not shown in the drawings, the absorbent pad 3 may also includeother features, such as a liquid dispersing layer and a reinforcinglayer made, for instance, of tissue or fabric.

The two casing sheets 1, 2 extend outwardly beyond the edges of theabsorbent pad 3, and are mutually joined around the whole of theperiphery of the absorbent pad 3, thereby enclosing the absorbent padbetween the casing sheets 1, 2. The casing sheets are joined togethersuitably with the aid of some appropriate, known technique, for exampleby gluing or heat-welding or ultrasonic-welding.

Two flexible pieces of material or flaps 4, 5 of generally the samelength as the two casing sheets are firmly secured along the side edges6, 7 of the liquid-impermeable sheet sheet 2. The flaps 4, 5 extendinwardly over the liquid-impermeable casing sheet 2, and meet at thelongitudinal center line 8 of said sheet. The flaps 4, 5 may, forinstance, be made of fabric or plastic film material. In order tofacilitate handling of the sanitary napkin when used, the flaps 4, 5preferably have a certain degree of stiffness, so that they will notwrinkle or fold when applied to a pair of underpants or like garment.Flaps which have a given degree of stiffness will also assist incounteracting compression of the napkin during use.

The sanitary napkin shown in FIGS. 1-3 is placed in the crotch part of apair of underpants or like garment 9 having elastic leg edges 10, 11,such that the material of the underpants 9 will be located between theliquid-impermable sheet 2 of the napkin and the flexible flaps 4, 5.

The side edges 6, 7 of the casing sheets 1, 2 and the flaps 4, 5 arecurved so as to conform as close as possible to the curvature of the legedges 10, 11 of the underpants 9. Since the width of the crotch part canvary between different makes of underpants or like garment, it is, ofcourse, impossible to provide a sanitary napkin which will fit exactlyall types of underpants. When testing 126 pairs of randomly selectedladies' panties of different sizes and models, it was found that thecrotch part of a pair of ladies' panties had an average width of 65 mm,measured at the narrowest crotch region. Accordingly, it is appropriatefor the sanitary napkin to have approximately this width at itsnarrowest part. However, it is not necessary for the width and shape ofthe napkin to correspond totally to the shape and the width of thecrotch of the underpants 9. If the crotch is slightly narrower than thedistance between the edge joins 12, 13 of the napkin, this will simplymean that the edges 10, 11 of the underpants will not reach fully out tothe edge joins 12, 13, and that the sanitary napkin will be able to movelaterally to a limited extent when in use. When the crotch is broaderthan the sanitary napkin, it is necessary to draw or gather the legedges 10, 11 of the underpants 9 slightly together, so as to enable thenapkin to be fitted in the underpants. Any pleats or folds which mightform in the crotch of the underpants as a result hereof will lacksignificance to the function of the napkin and will not have anyinfluence on the wearer's comfort.

When the sanitary napkin is carried in a pair of underpants 9, thenapkin will conform to the shape of this part of the wearer's body andis imparted a curved configuration in the longitudinal direction of thenapkin. When the napkin is curved longitudinally, tension forces aregenerated in the flexible flaps 4, 5 on the outside of the underpants 9,causing the flaps 4, 5 to press against the underpants 9 so as to clampthe underpants firmly between the flaps 4, 5 and the liquid-impermeablesheet 2 of the napkin, as shown in FIG. 3. The napkin is hereby held inposition in the underpants 9, without needing to use separate securingdevices, such as pressure-sensitive adhesive or adhesive tape.

FIG. 4 illustrates a sanitary napkin whose configuration is particularlyadvantageous from the aspect of manufacture. Similar to the napkinillustrated in FIGS. 1-3, the sanitary napkin of the FIG. 4 embodimentincludes an absorbent pad 3 which is enclosed between two casing sheets1, 2, and flexible flaps 4, 5 which are attached to theliquid-impermeable casing sheet 2 and firmly secured to the longitudinaledges 6, 7 thereof. The liquid-impermeable sheet 2 and the flexibleflaps 4, 5 of the sanitary napkin are provided with regions 14, 15 ofpressure-sensitive adhesive, for securing the napkin inside a pair ofunderpants or like garment 9. The adhesive is provided on that side ofthe flaps 4, 5 which faces towards the liquid-impermeable sheet 2. Priorto use, the adhesive regions 14, 15 are protected by a strip 16 ofmaterial treated with a release agent. The protective strip 16 istreated with a release agent on both sides thereof, thereby serving as aprotective layer both for the adhesive regions 14 on theliquid-impermeable sheet 2 and for the adhesive regions 15 on theflexible flaps 4, 5.

When the napkin is to be used, the protective strip 16 is removed fromthe adhesive and the napkin is placed in the crotch of a pair ofunderpants 9, with the flexible flaps 4, 5 secured to the outside of theunderpants. An adhesive or like substance is preferably used to securethe napkin to the underpants, since the flaps 4, 5 of a napkin of thekind illustrated in FIG. 4 are not self-locking in use, as distinct tothe flaps of the napkin described with reference to FIGS. 1-3. This ismainly because the edges 6, 7 of the FIG. 4 embodiment are straightinstead of curved. Furthermore, the flaps 4, 5 of the napkin accordingto FIG. 4 only take up a small part of the length of the napkin.

The napkin illustrated in FIG. 4 is particularly well suited formanufacture without material waste. The casing sheets and the materialin the flexible flaps and the protective strip which covers the adhesiveare all formed from pieces that are taken from endless webs of materialscapable of being glued or welded together. The absorbent pad ispreferably formed by air-laying the absorbent material form which thepad is made. The finished napkins are clipped or cut to a trapezoidalshape from an endless web. The final cutting stage can be effectedwithout any wastage of material, by arranging the napkins with theirbroader ends facing in alternate directions.

The construction of the sanitary napkin illustrated in FIGS. 5 and 6 isthe same as the construction of the napkin illustrated in FIG. 4, andincludes an absorbent pad 3 enclosed between two casing sheets 1, 2, andflexible flaps 4, 5 attached to the liquid-impermeable sheet 2 andfastened along the side edges 6, 7 of said sheet. Both the flexibleflaps and the liquid-impermeable sheet have regions 14, 15 ofpressure-sensitive adhesive, which are covered with a protective layer16, prior to the napkin being used. However, the napkin illustrated inFIGS. 5 and 6 differs from the napkin illustrated in FIG. 4, in that thelongitudinal side edges 6, 7 are not inclined to the same extent inrelation to the longitudinal center line 8 of the napkin, and in thatthe napkin is somewhat narrower than the napkin of the FIG. 4embodiment. The napkin hereby obtains a slightly different functioningmode.

When a napkin according to the embodiment illustrated in FIGS. 5 and 6shall be placed within a pair of underpants 9 or like garment, theprotective strip 16 is removed so as to first expose the adhesiveregions 14, 15. The side-flaps 4, 5 are then unfolded away from theabsorbent pad 3. The flaps 4, 5 therewith forcibly raise parts of theedge joins 12, 13 projecting outwardly of the absorbent pad, so as toform uplifted liquid barriers 18, 19 on both sides of the absorbent pad3. The extension of the liquid barriers 18, 19 in the longitudinaldirection of the napkin will, of course, depend on the size of the edgejoins 12, 13 connected to a respective side flap 4, 5. That part of theedge joins 12, 13 which can be raised by each flap 4, 5, however, ismuch longer than the actual join 12, 13 between the flaps 4, 5 and thecasing. Consequently, it is possible to obtain effective and efficientupstanding liquid barriers 18, 19 even with relatively small flaps 4, 5.This is, of course, particularly advantageous from the aspect ofdiscretion and also with view to the ease with which the napkin can behandled.

FIG. 6 is a sectional view illustrating how the sanitary napkin iscarried in the crotch region of the user. The napkin is secured in thewearer's underpants 9 by means of regions 14 of pressure-sensitiveadhesive provided at the end parts of the napkin on theliquid-impermable sheet 2. The flexible flaps 4, 5 are folded around theleg edges 10, 11 of the leg openings of the underpants 9 and are securedto the outside of said underpants. Regions 15 of pressure-sensitiveadhesive are also provided on the flaps 4, 5 for this purpose.

Because the absorbent pad 3 of the sanitary napkin is slightly narrowerthan the crotch part of the underpants 9, the flaps 4, 5 will extendlaterally outwards from each long edge of the elongated absorbent pad,prior to folding the flaps 4, 5 around the leg edges 10, 11 of theunderpants 9. When the napkin is worn, the elastic devices in the legedges 10, 11 will exert a given tension force on the napkin, so that theabsorbent pad 3 and those parts of the flaps 4, 5 which are locatedbetween the leg edges 10, 11 will be stretched in the transversedirection of the napkin. In this way, the major part of the edge joins12, 13 along the long sides of the absorbent pad 3 will be held raisedwhile the napkin is worn. Such uplifted barriers 18, 19 are particularlyeffective against leakage of body fluid over the edges of the napkin,and also against the spreading of liquid into the side-flaps 4, 5 ofsaid napkin. Because the liquid-impermeable sheet 2 of the napkinextends out into the upraised casing edges 18, 19, and because theside-flaps 4, 5 are made of separate pieces of material, there is norisk of liquid spreading across the liquid barriers 18, 19. It ispossible, and in fact suitable, to produce the flaps 4, 5 from aliquid-permeable material. The flaps 4, 5 are mainly intended tofunction as means for securing and stretching an absorbent article in apair of underpants or like garment, and need not have liquid obstructingproperties. Thus, by producing the flaps from an air-and-moisturepervious material, it is possible to provide a sanitary napkin which iscooler and more comfortable to wear than earlier known sanitary napkinsin which the flaps form liquid-impervious leakage barriers.

Although the invention has been described with reference to sanitarynapkins, it will be understood that the invention can be applied equallyas well to incontinence guards.

The invention shall not be considered limited to the described andillustrated embodiments thereof. For example, it is possible to vary theshape and the size of the flaps of the article and of the absorbent pad.The flexible flaps need not meet at the centre line of the article, butmay overlap one another or may simply extend slightly inwards towardsthe centre line from each side edge.

Furthermore, the article may be of the kind in which the casingcomprises a single sheet of material which is folded and sealed aroundthe absorbent pad.

The means used to secure the article in place in a pair of underpantsmay be different to those described and illustrated. For example, thearticle may include friction means or self-gripping tape, or may havepressure-sensitive adhesive provided in patterns other than thoseillustrated and described.

The outwardly projecting flaps may be produced from any appropriate typeof material, which may be elastic, for instance.

I claim:
 1. An absorbent article, intended to be worn in the crotch partof a pair of underpants and including: an elongated absorbent padenclosed in a casing and flexible flaps which are attached to respectivelong edges of said pad, each said flap being formed of a separatematerial piece and intended to be folded around leg edges of theunderpants in use, so as to protect the underpants against soiling, eachflap having an edge part which coincides generally with a correspondingedge part on the article casing; said flaps and said casing beingmutually joined within an attachment area located in the mutuallycoincident edge parts, with the flaps extending inwardly over theabsorbent pad on the side of the casing remote from the wearer when thearticle is in use, and said flaps being foldable along a longitudinalaxis inwardly of the attachment area.
 2. An article according to claim1, wherein the long edges have a concave curvature, whereby the articlehas generally the same shape as the crotch part of a pair of underpants.3. An article according to claim 1, wherein the flaps extend along thefull length of side edges of the article.
 4. An article according toclaim 1, wherein the casing includes a liquid-permeable sheet on thatside of the article which faces the wearer in use, and aliquid-impermeable sheet on that side of the article which is distalfrom the wearer in use, said two sheets projecting out beyond edges ofthe absorbent pad and being mutually joined around the full periphery ofsaid absorbent pad; and said flexible flaps being secured to casingedges of the liquid-impermeable sheet projecting out from the absorbentpad.
 5. An article according to claim 4, further including regions ofpressure-sensitive adhesive arranged on the liquid-impermeable sheet. 6.An article according to claim 5, further including regions ofpressure-sensitive adhesive arranged on the flexible flaps.